Injection moulded products may need attached bodies, such as electronic components attached on a surface of the injection moulded product or embedded into the product. Attachment techniques according to prior art are complicated because the body must be attached to the product after the injection moulding, i.e. to the ready injection moulded product. Films or glue must be laid to the surface of the injection moulded product or the surface of the body after the injection moulding to attain a joint between the injection moulded product and the body. If the body is to be embedded in the injection moulded product, air often remains inside the product producing a cave near the body and weakening the strength of the injection moulded product.